Homeowners are being advised to take prompt action regarding a specific plant known as Japanese knotweed, which is currently entering its most aggressive growth phase between April and October.
Experts are cautioning that ignoring Japanese knotweed can result in significant damage to buildings, gardens, and infrastructure. The plant’s threat was emphasized during a recent episode of BBC Morning Live, where consumer advocate Louise Minchin discussed its surging growth during the peak season alongside presenters Greg Rutherford and Helen Skelton.
Minchin highlighted the rapid re-emergence of Japanese knotweed after the winter dormancy period, emphasizing the importance of identifying and controlling it during the spring and summer months. Originally introduced to the UK in the mid-19th century as an ornamental Victorian garden plant, Japanese knotweed has now become one of the most destructive invasive species in the country.
According to the Royal Horticultural Society, Japanese knotweed is categorized as an invasive non-native plant that spreads rapidly through underground rhizomes and proves extremely challenging to eradicate once established. The plant can penetrate patios, pavements, drains, and brickwork, with Minchin describing it as a menace that can disrupt lives if not addressed promptly.
The Environment Agency has previously warned that even small fragments of the plant can regrow, increasing the risk of spreading, especially during active growth periods when homeowners may attempt DIY removal.
Property experts emphasize that Japanese knotweed remains a major concern in the UK housing market, with mortgage lenders often refusing loans for properties where the plant is present unless a professional management plan is in place. Treatment programs can be lengthy and costly, particularly when infestations are left unchecked.
The plant’s underground rhizome system can extend deep underground and wide, enabling it to regenerate even after apparent removal, making control particularly challenging during the summer growth period. Disposal of Japanese knotweed is strictly regulated in the UK, with contaminated material considered controlled waste that must be handled by licensed carriers to prevent further spread.
Legal experts stress that sellers must disclose the presence of Japanese knotweed on property forms; failure to do so can lead to misrepresentation claims and disputes over property values. Undisclosed cases of knotweed can result in significant legal expenses if it affects property sales or necessitates remedial action.
Specialist surveys and trained detection dogs are now being employed to identify hidden infestations, including underground growth that becomes more detectable during peak growth periods. The focus is increasingly on long-term management plans involving herbicide treatment over multiple growing seasons rather than complete eradication.
Homeowners are strongly advised to take immediate action upon spotting signs of Japanese knotweed during peak growth periods, as delays can escalate treatment costs significantly and complicate future property transactions.